For any of you who read my blog via email, you are reading the blog thanks to Aaron Swartz who, among his many accomplishments, helped to create RSS, which is the technology behind those emails. For a heartfelt reflection from someone who knew Aaron Swartz well, here is danahboyd: processing the loss of Aaron Swartz. And here is a wonderful documentary film: The Internet's Own Boy: The Story of Aaron Swartz. Be warned: you will cry. But you will feel both awe and gratitude, too. (The RSS part starts at 8 minutes in.)
So, here are the books in PDF format - please download them, read them, share them! Perhaps some of you have downloaded one or two of them over the years, but this is the first time I have put all four in one place. The errata lists for each are available at their respective websites.